Microsoft is an even better example of a massive company continually competing. Their dev/tech products and tools have gotten magnitudes better in recent years.

Huh? MS is the perfect example of how monopolies cause things to stagnate. It was only when new technology paradigms allowed for the growth of companies like Google and Amazon (wrt AWS) did MS turn around.

IE stagnated for years after MS killed Netscape. No company has really ever challenged Windows on desktop PCs. It was only when new platforms like the Internet and mobile computing came along that provided space for upstarts did MS start competing again.

Sure, but that's the example of monopolies facing competition when they turn bad. Sometimes that takes a new platform shift, other times its just a better product, but either way if there's new value then the monopoly breaks down.

I think if anything, the problem today is companies that could be challengers just end up selling to the very incumbent they're competing against.

In the instances you’ve described where “monopolies” haven’t dominated the market, they were not actually monopolies because they didn’t have total ownership of the market.

A company can be a tech giant and still not be classed as a monopoly. Which are the kind of examples you’re think of.

For those that lived through the Windows 9x desktop monopoly in the 90s, the Internet Explorer monopoly, etc, they will see Microsoft as a prime example of how monopolies are terrible.

In fact the few areas where you actually see Microsoft improve things are in areas where they have experience but don’t actually have a monopoly (eg IDEs).